Pipe gripping tool

ABSTRACT

A hand tool usable for gripping pipes or other objects comprises an opposed pair of jaws pivoted on integral extensions at a point remote from the jaws. One jaw pivotably mounts an elongated handle with pawl means at the pivoted end thereof. A leaf chain extends from the handle, over the pawl means to the opposite jaw where it is pivotably anchored. The handle may be selectively pivoted to engage the chain with the pawl means, thereby forcing the jaws together, or to disengage the pawl means from the chain, thereby facilitating free movement of the jaws together or apart.

United States Patent [1 1 Nockleby PIPE GRIPPING TOOL [76] Inventor:Raymond B. Nockleby, Rt. 1,

Kalispell, Mont. 59901 [22] Filed: Mar. 26, 1973 [21] Appl. No.: 344,567

[52] US. Cl 81/111, 81/67 R, 81/329 [51] Int. Cl B251) 13/34 [58] Fieldof Search 81/43, 67 R, 91 B, 111, 81/329, 384; 30/190, 192, 251

[5 6] References Cited UNITED STATES PATENTS 797,340 8/1905 Brooks81/111 1,063,153 5/1913 Benediet.... 81/67 2.932.226 4/1960 Seppola81/67 R X 3,566,721 3/1971 Nockleby 81/384 3,618,431 11/1971 Nockleby81/329 June 11, 1974 Primary Examiner-Othell M. Simpson AssistantExaminer-James G. Smith Attorney, Agent, or FirmSt. John & Roberts Wells5 7 ABSTRACT A hand tool usable for gripping pipes or other objectscomprises an opposed pair of jaws pivoted on integral extensions at apoint remote from the jaws. One jaw pivotably mounts an elongated handlewith pawl means at the pivoted end thereof. A leaf chain extends fromthe handle, over the pawl means to the opposite jaw where it ispivotably anchored. The handle may be selectively pivoted to engage thechain with the pawl means, thereby forcing the jaws together, or todisengage the pawl means from the chain, thereby facilitating freemovement of the jaws together or apart.

5 Claims, 7 Drawing Figures PIPE GRIPPING TOOL BACKGROUND OF THEINVENTION The present invention relates to tools havingjaws positionedby relatively movable plural handles and more particularly to such toolsutilized to manually grip items so they can be released simply byreleasing the manual grip.

It is often desirable to utilize a tool which provides integral meansfor tightly gripping an object without requiring the same amount ofexertion by the user. It is further desirable to utilize such a toolwhich also provides means for easily and quickly adjusting the distancebetween the gripping jaws.

A search of prior art has revealed the following relative United Statespatents of interest:

U.S. Pat. No. 3,618,431 granted to R. B. Nockleby; U.S. Pat. No.3,566,721 granted to R. B. Nockleby; U.S. Pat. No. 2,932,226 granted toA. Sepolla; U.S. Pat. No. 639,812 granted to T. Jensen.

The first two patents cited above granted to me on Nov. 9, 1971 and Mar.2, 1971 respectively are similar to the present invention only in thatboth include an opposed set of jaws, each having an extension thereonwith the extensions being hinged to each other at a point remote fromthe jaws.

The Seppola patent shows a pipe wrench using a flexible chain as thegripping element. The apparatus does not show rigid jaws that aremovably positioned by means of a chain which acts as a positioning andtensioning member during gripping of an object between rigid jaws.

The T. Jensen patent discloses a monkey wrench having an adjustablepivot and including three handles. The pivot is adjustable by means of athreaded shaft and a knob threadably engaged thereon.

The apparatus of the present invention comprises a rigid pair of jawseach having an extension thereon and hinged to each other at a pointremote from the jaws. An elongated handle is pivotably mounted to one ofthe jaws. A flexible linkage is anchored to the opposite jaw and extendsthrough an opening in the one jaw to the handle. The handle includesmeans for engaging the linkage and applying a levered force to it,thereby pulling the jaws relatively together. This levered force isapplied as the handle is pivoted toward the hinged extensions. Bypivoting the handle away from the hinged extensions, the linkage isdisengaged from the handle, thereby allowing free adjusting movement ofthe jaws relative to one another.

SUMMARY OF THE INVENTION The apparatus disclosed herein comprises a handtool having opposed jaws and extensions on the jaws which are hinged toeach other at a point remote from the jaws. An elongated handle ispivotably mounted at one end thereof to one of the jaws, the pivot axesfor said extensions and said handle being parallel.

A flexible linkage is anchored at one end to the remaining jaw and isconnected by means of a tension spring to the handle. The handleincludes pawl means at one end thereof for releasably engaging thelinkage to pull the anchored end and thereby the jaws together.

It is a first object of my invention to provide a hand tool which hasmore gripping leverage than a regular plier-type tool.

A BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofthe tool showing portions thereof broken away;

FIG. 2 is a plan view of the apparatus shown in FIG.

FIG. 3 is a view similar to FIG. 1, only showing the tool in anoperative position with an object shown in phantom lines between thejaws;

FIG. 4 is a fragmentary view showing an inoperative position of thehandle;

FIG. 5 is a fragmentary isometric view of a portion of the tool handle;

FIG. 6 is a fragmentary elevational view of the hinged end of theextension with anextension formed thereon; and

FIG. 7 is a fragmentary elevational view of the hinged end of the handlewith an integral extension formed thereon.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings ingreater detail, and especially to FIGS. 1 and 3, there is shown apreferred form of the invention basically comprising an opposed pair ofjaws 10 and 11 having a pair, of extensions 12 and 13 respectivelyextending outwardly therefrom. Extensions 12 and 13 are hinged togetherat a point remote from the jaws for pivotal movement about an axisdefined by a hinge pin 14.

The jaws are longitudinally concave to conform to objects such as thepipe 15 shown in FIG. 3 by phantom lines. The shape of the jaws, howeveris not intended to be restricted to such shapes nor is utilization ofthe tool to be restricted to specific work pieces. Pipe 15 is exemplaryof only one specific work piece that I have found to be easily workablewith the present invention.

An elongated handle 16 is pivotally mounted to a forward end 17 ofextension 12 by means of a pivot pin 18, the axis of which is parallelto the axis defined by hinge pin 14. Pivot pin 18 provides a leverfulcrum for the gripping action of the jaws l0 and 11 which will bediscussed in greater detail below.

Handle 16 is mounted within an opening 20 extending vertically throughthe forward end 17 of extension v 12. Opening 20 is longitudinallyelongated to allow free pivotal movement of the handle relative toextension 12 between the positions shown in FIGS. 1 and 4. Handle 16 isoperatively connected to extension 13 adjacent jaw 11 by a flexiblelinkage comprised of a conventional leaf chain 22 and a tension spring25.

Chain 22 includes a plurality of links 19 pivoted end to end by pins 21which extend outwardly from the link sides as shown in FIG. 2. The chainis connected at one end to extension 13 by a pivot pin 23. The end link19 and end 23 fit within a recess (not shown) in extension 13 whichallows pivotal movement of that link about an axis parallel to the axesof pins 14 and 18.

Chain 22 extends upwardly from pin 23 through opening and along a guidechannel 24 which is formed as an integral part of handle 17. The otherend of chain 22 is connected to one end of spring 25 which extendstherefrom to an outer end 29 where it is anchored to a downwardlyprotruding lip 28.

Spring 25 is utilized to urge the chain toward a straight line betweenpin 23 and anchor lip 28 on handle 16. This condition is prevented, whenthe handle is in a gripping position, by a pawl means at a verticallyopen inner end 30 of handle 16.

The open end 30 of handle 16 is defined by trans versely spaced verticalwall sections 30a and 30b. The wall sections are spaced apart a distancesufficient to allow free passage of the chain links therebetween, butinsufficient to allow passage of the pins 21, which must slide over thetop wall edges.

The pawl means is formed in the wall sections along the top edges andcomprises two sets of transversely aligned recesses, 31 and 36respectively for engaging the pins 21. The recesses are formed assemi-circles including not more than 180 with their transverse axesequally spaced from pivot pin 18 and parallel to the .center axes of thechain link pins 21. The distance between the axes of recesses 31 and 36is less than the distance between axes of adjacent chain link pins 21.By spacing the recesses as such, the pawl means is assured of engaging apin within one or the other set of recesses with a minimal amount ofmovement of the handle 16 toward a closed position, regardless of therelative position of the chain link pins 21. This feature may best beunderstood with reference to FIG. 4 wherein a pin 21a is shown in thepivotal path of recesses 36. If, however, the size of the object 15necessitated that the jaws be spaced apart with the pin 21a positionedbetween recesses 36, 31, the pin would then lie in the pivotal path ofrecesses 31 and would be engaged thereby (as shown in F168. 1,2, and 5)following approximately the same amount of handle movement required asdescribed to engage pin 21a in recesses 36 as shown in H6. 4.

FIG. 4 partially illustrates the tool in an inoperative position whereinthe chain is disengaged from the pawl means and is thus extendiblerelative to handle 16, by expanding the spring 25. Such disengagement ofthe pawl means from the chain frees the jaws for pivotal movement aboutthe axis of hinge pin 14. Such free movement facilitates positioning ofthe jaws relative to one another sufficiently apart to allow an objectto be received therebetween.

Once the jaws are positioned on either side of an object, as shown inFIG. 3, the handle may be pivoted toward extension 12 to engage a pin 21in recesses 31 or 36. Further pivotal movement of the handle in thisdirection creates a tensile force on the length of chain between the pin21 engaged by recesses and the pin 23 which mounts the end of the chainto extension 13. This force serves to pull the jaws 10 and 11 together,thereby clamping the object. It may be noted that the distance betweenpin 18 and recesses 31, 36 is substansion 34 as shown in FIG. 7, andextension 13 may be provided with an additional extension 33 as shown inFIG. 6, which together will improve the leverage against chain 25 toprovide even greater gripping force to jaws 10 and 11.

As may be noted in FIG. 3, the chain may be deflected by the peripheryof the object when gripped. This feature is advantageous in two ways.Firstly, the tension on the chain during gripping action creates anadditional grip force which is offset from the opposed forces of thejaws. Secondly, the chain provides an additional surface in contact withthe object and therefore aids to prevent slipping of the jaws on theobject.

Also shown in FIG. 6 is a torsion spring 35 loosely fitted around hingepin 14 with its ends in contact with extensions 12, 13 as shown. Spring35 may be used to bias the extensions 12, 13 and thereby jaws 10, 11apart with handle 16 in the inoperative position shown in FlG. 4 therebyequalizing or overcoming the tensile force of spring 25 which normallywould urge the jaws 10 and 11 together.

Operation of the tool may now be easily understood with reference toFIGS. 1, 3 and 4. To first grip an object, the operator pivots thehandle 16 to the position shown in FIG. 4, thereby disengaging the chain22 from the notches 31. The jaws 10 and 11 are thereby free to pivotabout the axis of hinge pin 14 together or apart a distance slightlygreater than the size of the object to be gripped. Once the object hasbeen received between the jaws 10 and 1 l, the handle 16 may again bepivoted toward the extensions 12 and 13 pivoting the pawl means toengage a pin 21 of the chain 22. Further force on the handle 16 towardthe extensions then forceably pulls the jaws together against theobject. To release the object, theoperator simply allows handle 16 toreturn to a normal positionthereby relaxing the gripping force on thejaws.

By providing such a simple, yet efficient gripping means, 1 have foundthat the tool may be used ratchet style by first gripping the object andtwisting it, releasing the handle, then regripping the object andtwisting again.

It may be obvious that various changes and modifications may be madewith respect to the above description and attached drawing. Therefore,only the following claims are intended to define this invention.

What I claim is:

l. A hand tool usable to grip items by hand action, comprising:

a first jaw;

a second jaw opposing said first jaw;

a first extension on said first jaw;

a second extension on said second jaw, said first and second extensionsbeing hinged to each other at a point remote from the jaws;

an elongated handle pivotably mounted at one end thereof to said secondextension adjacent said jaw, the pivot axes for said extensions and saidhandle being parallel;

flexible non-extensible linkage anchored at one end to said firstextension adjacent said first jaw;

a tension spring connected at one end to said linkage and at the otherend to said handle adjacent an end thereof opposite said one end;

pawl means at said one end of said handle, integral therewith andradially spaced from said pivot axis and operative by application ofinward force on said handle relative to said extensions to releasablyengage said linkage and pull said anchored end, and thereby said firstjaw, toward said second jaw;

said pawl means being spaced radially from the pivot axis of said handleto provide a lever arm thereby multiplying said inward force on saidjaws.

2. The tool defined in claim 1 further including means for mounting saidhandle for pivotable movement between:

a first position wherein said pawl is disengaged from said flexiblelinkage, thereby facilitating free movement of said jaws together orapart, the amount of such movement being restricted only by the lengthof said flexible linkage and expanded length of said tension spring, and

a second position wherein said pawl is engaged with said flexiblelinkage, thereby limiting the jaws to relative movement in response onlyto pivotal movement of said handle.

3. The tool defined in claim 1 wherein said flexible linkage comprises aconventional flat link pitch chain including a plurality of flat linkspivotably held end to end by a plurality of transverse pins;

and wherein said pawl comprises at least one open recess formed withinsaid one end of said handle complementary in configuration to saidtransverse pins and adapted to receive a pin therein;

said recess being radially spaced from the pivot axis of said handle ata point between said axis and said second jaw.

4. The tool defined in claim 1 wherein said flexible linkage comprises aconventional flat link pitch chain including a plurality of flat linkspivotably held end to end by a plurality of transverse pins having endsprotruding transversely outward from the links;

said handle further including transverse spaced wall sections integralwith said handle at said one end, the wall sections being spaced apart adistance greater than the transverse thickness of said chain links andequal to or less than the distance between the ends of said transversepins;

said wall sections having top edge surfaces radially spaced from thepivot axis of said handle; paired sets of recesses complementary inconfiguration to said pins formed in said top edge surfaces along axesparallel to said pins and equidistant from the pivot axis of the handle,adapted to selectively receive and release said pins in response topivotal movement of said handle.

5. The tool defined in claim 4 wherein the axes of the recesses arespaced apart a distance less than the dis tance between successive pinsof said chain.

1. A hand tool usable to grip items by hand action, comprising: a first jaw; a second jaw opposing said first jaw; a first extension on said first jaw; a second extension on said second jaw, said first and second extensions being hinged to each other at a point remote from the jaws; an elongated handle pivotably mounted at one end thereof to said second extension adjacent said jaw, the pivot axes for said extensions and said handle being parallel; flexible non-extensible linkage anchored at one end to said first extension adjacent said first jaw; a tension spring connected at one end to said linkage and at the other end to said handle adjacent an end thereof opposite said one end; pawl means at said one end of said handle, integral therewith and radially spaced from said pivot axis and operative by application of inward force on said handle relative to said extensions to releasably engage said linkage and pull said anchored end, and thereby said first jaw, toward said second jaw; said pawl means being spaced radially from the pivot axis of said handle to provide a lever arm thereby multiplying said inward force on said jaws.
 2. The tool defined in claim 1 further including means for mounting said handle for pivotable movement between: a first position wherein said pawl is disengaged from said flexible linkage, thereby facilitating free movement of said jaws together or apart, the amount of such movement being restricted only by the length of said flexible linkage and expanded length of said tension spring; and a second position wherein said pawl is engaged with said flexible linkage, thereby limiting the jaws to relative movement in response only to pivotal movement of said handle.
 3. The tool defined in claim 1 wherein said flexible linkage comprises a conventional flat link pitch chain including a plurality of flat links pivotably held end to end by a plurality of transverse pins; and wherein said pawl comprises at least one open recess formed within said one end of said handle complementary in configuration to said transverse pins and adapted to receive a pin therein; said recess being radially spaced from the pivot axis of said handle at a point between said axis and said second jaw.
 4. The tool defined in claim 1 wherein said flexible linkage comprises a conventional flat link pitch chain including a plurality of flat links pivotably held end to end by a plurality of transverse pins having ends protruding transversely outward from the links; said handle further including transverse spaced wall sections integral with said handle at said one end, the wall sections being spaced apart a distance greateR than the transverse thickness of said chain links and equal to or less than the distance between the ends of said transverse pins; said wall sections having top edge surfaces radially spaced from the pivot axis of said handle; paired sets of recesses complementary in configuration to said pins formed in said top edge surfaces along axes parallel to said pins and equidistant from the pivot axis of the handle, adapted to selectively receive and release said pins in response to pivotal movement of said handle.
 5. The tool defined in claim 4 wherein the axes of the recesses are spaced apart a distance less than the distance between successive pins of said chain. 